Infant formulae have been developed, which allow for substituting breast feeding of infants.
Such infant formulae should wholly satisfy the nutritional requirements of infants until the introduction of appropriate complementary feeding. Further, taste is important, as at least the parents prefer infant formulae having a non-bitter taste. Infant formulae which instead of ordinary cow's milk comprise hydrolyzed milk protein, e.g. partially hydrolyzed whey protein or extensively hydrolyzed casein, are often used as such formulae are less allergenic and still have an acceptable taste.
Processes for preparation of partial hydrolysates described in the literature often comprise use of pancreatic enzymes such as trypsin preparations produced by extraction of porcine pancreatic tissue (see, e.g., WO9304593 A1, U.S. Pat. No. 5,039,532 A). Some of the processes described comprise use of a mixture of trypsin and chymotrypsin. E.g., EP0353122 A discloses a process for preparing a hypoallergenic whey protein hydrolysate using a mixture of trypsin and chymotrypsin, wherein the ratio of the chymotrypsin/trypsin activities is between 1.5 and 3.0. In EP0631731 A1, a mixture of trypsin and chymotrypsin having a trypsin to chymotrypsin ratio of 1.3 to 18 in USP units, more preferably 4 to 6, is said to typically result in a hydrolysate of desirable properties.
For several reasons, use of proteolytic enzymes produced from a microorganism may confer benefits. For example, enzyme production from a microorganism is efficient and easy to control. Therefore, such enzymes can be produced in large quantities and at high purity. Also, use of microbial enzymes will help overcoming increasing QA related difficulties as regards extraction of enzymes from an animal source.
One object for the present inventors has been to develop a process for making a milk-based protein hydrolysate with microbially produced enzymes which has a low allergenicity. Another object has been to develop a process for making a milk-based protein hydrolysate with microbially produced enzymes which has a protein fragment profile having similarity to the protein fragment profile of hydrolysates prepared with extracted preparations comprising trypsin and chymotrypsin. Another object has been to develop a process for making a milk-based protein hydrolysate with microbially produced enzymes which has an acceptable taste. In particular, it would be highly desirable to have a partial whey protein hydrolysate which has low allergenicity, which has a protein fragment profile having similarity to the protein fragment profile of hydrolysates prepared with extracted preparations comprising trypsin and chymotrypsin, and/or which has an acceptable taste, in particular as regards bitterness.